Thermoplastic vulcanizates based on crystalline polyolefin thermoplastics and vulcanized polyolefin rubbers have found wide commercial use. Due to the low melting point of the crystalline polyolefin thermoplastic phase these vulcanizates may be limited to use temperatures below 150.degree. C. Due to the substantially hydrocarbon nature of both phases of these thermoplastic vulcanizates they experience high swelling in hydrocarbon oil such as ASTM#3 oil. Therefore, it would be desirable to develop a thermoplastic vulcanizate from a polar thermoplastic with a rubber with sufficient polarity to minimize swelling with hydrocarbon oils. U.S. Pat. No. 5,574,105 describes a triblend thermoplastic elastomer having a higher use temperature that may include a polyamide thermoplastic phase, a crystalline polyolefin phase and a brominated copolymer of paramethylstyrene and isobutylene. The patent further defines a compatibilizing agent such as can be prepared from the reaction product of a polyamide (nylon) and a carboxyl functionalized polypropylene by melt mixing nylon 6 with a propylene grafted with from 0.1 to 2.0 weight percent maleic anhydride. These compositions have very good elongation. They have relatively high shore D hardness.
U.S. Pat. Nos. 5,003,003 and 5,525,668 (a division of the first) describe thermoplastic elastomer compositions from dispersing a polymonoolefin elastomer phase containing functionalized EPM or EPDM in a polyamide resin. The functionalization of the EPM or EPDM improves the compatibility of the EPM or EPDM with the polyamide and results in improved properties for thermoplastic vulcanizates therefrom. While these compositions have a desirable polar thermoplastic phase they still have a substantially nonpolar hydrocarbon rubber phase capable of high swelling in hydrocarbon solvents.
U.S. Pat. Nos. 5,244,961 and 5,453,465 (a division of the first) disclose thermoplastic polyamide compositions modified with an elastomeric halogen containing copolymer of a C.sub.4 -C.sub.7 isomonoolefin and a paraalkylstyrene. The patents set forth the desirability of specified metal compounds capable of absorbing or reacting with hydrogen halide.
U.S. Pat. No. 5,238,992 describes a thermoplastic composition comprising a polyamide and a grafted copolymer of an isomonoolefin and alkylstyrene, such as a maleic anhydride grafted copolymer of isobutylene and paramethylstyrene. International publication WO 92/025 82, which was published Feb. 20, 1992 and is assigned to Advanced Elastomers Systems, describes thermoplastic compositions comprising a blend of a thermoplastic engineering resin which can be a polyamide and a halogen containing copolymer of a C.sub.4 -C.sub.7 isomonoolefin with paraalkylstyrene.